Oyster Cultch–Recruit Patterns Provide New Insight Into the Restoration and Management of a Critical Resource

Our objective was to quantify the relationship between oyster clutch mass (kg/m³) and density (oysters/m²) of live eastern oyster Crassostrea virginica on intertidal reefs in Suwannee Sound, Florida. We also evaluated the potential for a cultch-mass threshold below which recruitment declines (depensation) to inform oyster fishery management and restoration strategies.Our findings highlight the potential for a cultch-mass threshold below which eastern oyster recruitment may be limited, consistent with ecological theory and field observations that larval settlement depends on suitable substrate. Although the precise value of this threshold remains uncertain, model results suggest that recruitment may decline when cultch mass falls below approximately 20 kg/m³. We recommend that restoration and management efforts maintain cultch mass above a precautionary range of 5-20 kg/m³ to reduce the risk of reef collapse and support recovery. Further research is needed to more precisely estimate system-specific thresholds and better understand how cultch mass interacts with other oyster reef characteristics.

Casteel, J. L., Pine, W. E., Fisch, N.C., Moore, J. F., Richardson, M. S., Ahrens, R. N. M., Camp, E. V., Cahill, C. L., & Walters, C. J. (2025). Oyster cultch-recruit patterns provide new insight into the restoration and management of a critical resource. Marine and Coastal Fisheries, 17(4), vtaf018. https://doi.org/10.1093/mcfafs/vtaf018

Last updated by Pacific Islands Fisheries Science Center on 09/12/2025

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